Throughout the arts, it is old and common practice to ascertain the weight of objects and to determine forces exerted through and between related objects by weighing scales that translate and visibly display the weights and forces encountered in terms of, for example, pounds and fractions thereof.
For many years, weighing scales have utilized various forms of springs and related mechanical mechanisms through which encountered forces are directed and which include readout devices, often with dial faces and pointers, which serve to translate the amount of elongation or deflection of the springs into corresponding weight or force measurements. Other common scale structures include pivotally supported balance beams and counterweights with related structure to effect transmitting the weight of objects or of forces encountered onto the balance beams. The beams of such scales are calibrated and the counterweights are movable relative thereto and serve as markers to indicate the weight or forces encountered.
The great majority of the above noted common and familiar forms of scales are, by today's standards, inaccurate and unreliable. Further, due to the structural requirements and limitations embodied in those scales structures, they are frequently too large for use in many situations where space is at a premium and/or are so constructed and operate in such a manner that they cannot be effectively disposed and related to objects to be weighed or to related objects between which forces to be measured are encountered.
In recent years, with the advent of resistance-type strain gauges that are effective to measurably respond to slight displacement of the metal of metal parts to which the gauges are fixed and with the more recent advent of highly sophisticated bridge circuits which are effective to compensate for variations and/or deviations encountered in the resistance afforded by strain gauges, the prior art now provides electronic weighing and force-indicating scales wherein the weight of objects or forces to be measured are transmitted onto and through metal torque beams or tension rods on which strain gauges are fixed and which include electronic circuits to which the strain gauges are connected and which operate to accurately translate slight weight or force-induced movement or deflection of the beams and/or rods, sensed by the strain gauges, into electrical signals that are in turn translated into readable weight or force measurements by suitable electronic readout devices.
To date, to the best of our knowledge and belief, electronic weighing scales and the like which are provided by the prior art and in which strain gauges are utilized to sense and respond to the movement or displacement of a metal part in and through which weight and forces to be measured are conducted, are highly specialized, complicated and very costly scales or weighing structures.
To the best of our knowledge and belief, those prior art electronic weighing structures of the character referred to above are found embodied in large, complicated and costly structures and mechanisms such as bulk weighing scales, truck weighing scales, dynamometers, and the like. Apart from the foregoing, the prior arts use of strain gauges to measure forces is understood and believed by Applicants to be substantially limited to the application of such gauges in selected parts of pre-existing machines and devices where, for the purpose of controlling the operation of those machines and devices, it is desirable to know what the forces directed onto and through those selected parts are or might be.
To the best of our knowledge and belief, the prior art has not sought to provide a small, lightweight, compact electronic weighing scales structure which is suitable for regular or universal use in the great majority of those situations where old-fashioned spring-type scales or balance beam scales have long been used.